(i) Technical Field
The present invention relates to image pickup devices and focal plane shutters.
(ii) Related Art
For example, Japanese Patent Unexamined Application Publication No. 2010-34818 discloses an image pickup device with an electronic leading blade and mechanical trailing blades. After the electronic leading blade moves in the state where the trailing blades recede from an opening of a board, the trailing blades close the opening to perform exposure.
After an exposure operation is finished, image data are read from an image pickup element. During reading of the image data, the light has to be prevented from entering the image pickup element in consideration of an influence on the image data. Thus, the state where the opening is closed by the trailing blades has to be maintained for a predetermined period after the exposure operation.
In a case of using a normally open type shutter, the reading of the image date from the image pickup element is finished after the exposure operation, and then the trailing blades recede from the opening. This makes it possible to display a live view image on a liquid crystal display of a camera from the image pickup element in a real time manner, after the exposure operation.
Further, in continuous shooting, the reading of the image date from the image pickup element is finished after the exposure operation is finished, and then the trailing blades have to move away from the opening to perform a charging operation for a next exposure operation.
The trailing blades cannot be driven, until the image data are read from the image pickup element after the exposure operation. Thus, a shooting interval might not be shortened.